Numerical investigation of the effect of spray angle on emission characteristics of a diesel engine fueled with natural gas and diesel

Abstract

The addition of natural gas (NG) with diesel fuel is an attempt to increase the combustion efficiency of the diesel engine and to reduce nitrogen-based emissions in this investigation. A three-dimensional computational study has been carried out on the combustion chamber of a NG–dieseldual fuel engine. Standard k-ɛ turbulence model was used to incorporate the turbulence inside the combustion chamber. The spray angle inside the combustion chamber was varied from 100° to 150°. The flow characteristics such as pressure, temperature, and velocity distributions, combustion characteristic of apparent heat release rate, and emission characteristic of NO emission of dual fuel engine were investigated at different spray and crank angles. The results show that the maximum pressure inside the cylinder increased from 129 to 131 bar when the spray angle was varied from 100° to 150° at a crank angle of 360°. The maximum temperature was found to be 1602 K at a spray angle of 150° and at crank angle of 360°. The range of velocity inside the cylinder was from 5 m/s to 15.6 m/s. At the spray angle of 150°, the mass fraction of NO emission was 1.15 × 10−09 and was the least among the different spray angles. The optimized spray angle was chosen such that the combustion can take place properly with the least emission and was found to be 150°. The results of the present study were compared with the existing literature and are found to be in good agreement.